My local CVS sells The Interruption of Everything on a rack full of romance novels, and the drugstore turns out to be a pretty good literary critic. Terry McMillan once seemed headed for a career as “the world’s finest chronicler of modern life among African-American men and women,” as the San Francisco Chronicle said. But she’s devolved into Danielle Steel with a sense of humor.

The Interruption of Everything trundles out that emaciated cliché – a mother in her 40s who learns that her dull husband is having a “midlife crisis” (and, yes, it’s one of those “crises” that involves a younger woman). The plot careens soap-opera style through pregnancies, an arrest, an elopement, a sudden death, the onset of dementia, and a struggle for a gun at a California boutique, all of it driven by sitcom-level dialogue. Characters say “Dang” and “Whoa” and bemoan those well-known faults of men: “Overt stupidity. Promiscuity. Regressive behavior.” Marilyn, the perimenopausal heroine, says bizarrely that a hot flash feels like you’re “being dabbed with mild salsa.”

Faced with all of this, the editors seem to have given up. McMillan strings together as many as a half dozen independent clauses without punctuation. She sets up a subplot involving a man her heroine used to love — who just happens to buy a house three blocks away right after her husband decides to leave — and then, incredibly, drops it. You find more careful plotting in some of those paperback romances on the same rack at CVS.

But there’s a difference between McMillan and many other writers of books with metallic-embossed covers. At her best, she’s much funnier. She portrays the buoyant Christian faith of Marilyn’s mother-in-law, Arthurine Grimes, with wry affection instead of ridicule. You can’t help but smile when Arthurine says, “Is God your steering wheel or spare tire, Marilyn?” Or when, suspecting that her daughter-in-law is pregnant, Arthurine instructs her, “Remember, Jesus wasn’t planned, either.” At such moments, McMillan finds her literary groove and makes you hope she’ll widen it in future books.

Worst line: “We tried you on your cell but you didn’t pick up so we got a little worried since we didn’t know where your appointment was and we tried calling Leon at work but his assistant said he left early to pick up his son at the airport and against our better judgment we tried your house and Hail Mary Full of Grace answered and after she deposed us, I asked if she knew your doctor’s number and she said she had to think for a few minutes and while she was thinking I started thinking who else we could call and that’s when I remembered your GYN’s name was a hotel: Hilton!” Quick, send out a search party for the missing commas! The sentence reads like the winner of a Bad Hemingway Parody Contest.